Flux through a cube -> Qenc LAB (E&M Physics)

Hello, this is my first post here, I accidentally posted this in the wrong forum area at first. Hopefully it's okay that I don't follow the template for this question because I don't want students next semester to be able to just search up the question and find the answer right away online because this question is worth extra credit to the first team that comes up with an answer in the lab session (which is now over). I think that I found the right answer the the question (which I will post an image of), but I need help seeing if my answer is correct or if I did something wrong. Please ignore the math that I was doing on the actual question page, that was just me thinking of different ways of approaching the problem. Thank you in advance.